(a) Field of the Invention
The present invention relates to a multi-faceted valve head for hydraulic pump.
(b) Description of the Prior Art
Jacks are indispensable and convenient means of lifting loads. As scissor type jacks in particular facilitate operation in narrow or tight spaces, they have wide application. A jack in general utilizes an internal hydraulic thrust in conjunction with a lifting structure. In other words, all the lifting forces of the jack are provided by an oil hydraulic structure. It can therefore be seen that the construction of the multi-faceted valve head of an oil hydraulic pump is of utmost importance. As the multi-faceted valve head of conventional oil hydraulic pumps are comprised of a plurality of symmetrical and inter-communicated check valves, pressure adjusting valves, and oil passages, they have the following drawbacks:
1. As the multi-faceted valve head portion of the conventional oil hydraulic pump is comprised of a plurality of ducts that are inter-communicated or staggered, the ducts are often angular, which make the processing process very difficult. Besides, there are the problems of oil leakage or insufficient force due to holes or blocked communication. PA1 2. As the check valve s and pressure adjusting of the multi-faceted valve head of the conventional oil hydraulic pump are symmetrically disposed, the output of pressure may be uneven. PA1 3. Due to the above-mentioned uneven output of pressure in conventional multi-faceted valve head construction, the adjustment and control of pressure is also deficient. PA1 1. In the present invention, the oil chamber is communicated respectively with the oil return switch, the tube at the front end of the oil chamber, and the adjusting valve, and is connected to the conduit, the hydraulic oil in the oil chamber can be controlled by a pump, and it is only necessary to provide a check valve. Therefore, the processing procedures are relatively simple and easy to control, thereby reducing faulty product rates. PA1 2. The hydraulic oil pressure is directly output to the oil chamber by the pump, and the pressure can be controlled by means of the adjusting valve. Hence, the pressure is stable and adjustable according to the weight of the loads to be lifted.